1. Field of the Invention
This invention relates to a magnetic recording tape cassette, and more particularly to a magnetic recording tape cassette provided with means for preventing the magnetic recording tape from slackening.
2. Description of the Prior Art
There has come into wide use a portable type video recording system comprising a video camera associated with a miniaturized video tape recorder using a magnetic recording tape cassette. However, conventional portable type video recording systems are not so handy as an 8 mm cine camera since the video camera and the video tape recorder are separate units. Therefore there is a great demand for a portable video recording system comprising a video camera having a video tape recorder built therein. The video camera of this type will be referred to as a "built-in" type video camera, hereinbelow.
In the magnetic recording tape cassette for the video tape recorder, the recording tape must be prevented from accidentally slackening due to vibrations or mishandling by the user. Otherwise, the danger arises that the slack part of the tape may possibly project from the tape drawingout opening of the cassette to be damaged or that the loading operation which is to be effected after the cassette is loaded in the system which uses the cassette, e.g., a video tape recorder, cannot be correctly effected. Thus, conventionally the cassette has been provided with a braking device which permits rotation of the reels in the winding direction (the direction in which each reel is rotated to wind up the magnetic recording tape therearound) but does not permit rotation of the reels in the unwinding direction (the direction in which each reel is rotated to unwind the magnetic recording tape thereon). The conventional braking device includes, in both the Betamax system and the VHS system, a plurality of relatively small components.
In order to highly miniaturize the recording tape cassette to be loaded in a video tape recorder which itself is highly miniaturized so that it can be built in the builtin type video camera, the braking system must also be miniaturized. When the small components constituting the braking device are further miniaturized, workability in assembling the cassette is lowered due to the need to assemble the plurality of very small components of the braking device, which adds significantly to the manufacturing cost of the cassette.